Process of forming reconstituted tobacco foils



Jan 28, '1969 G. GRUNWALD ETAL 3,424,170

PROCESS OF FORMING RECONSTITUTED TOBACCO FOILS .Filed Oct. 6, 1967 INVENTORS 65026 620404 440 lmus-olerelcfl 770 Hfl/VZ-[R/K 8.12 BORG wALm; DfCfASifl,

BY #35 SOPHIE AME/VIE Hf/QMl/VEBOKGWALDZ' 19507555 A TWEIVEKST United States Patent 74,561 US. Cl. 131-140 Int. Cl. A24b 9/00, 13/00 8 Claims ABSTRACT OF THE DISCLOSURE Process of forming reconstituted tobacco foils. Tobacco particles of various sizes, including particles of more than 1000 diameter, are moistened and kneaded, without grinding, with a quantity by weight of an inert liquid such as water or glycol which is less than the weight of the particles. The thus moistened particles are then pressure rolled by a plurality of rollers rotating at different speeds under a pressure of more than 100 atmospheres to form a foil-like structure. The structure is then conditioned by adjusting its moisture content.

This is a continuation-in-part of Ser. No. 414,842, filed Nov. 30, 1964, now abandoned, for product and process.

In the processing of tobacco plants into tobacco products, relatively large amounts of small sized tobacco particles are obtained, the discarding of which would result in appreciable economic losses. For this reason, numerous processes have previously been proposed for the purpose of utilizing these tobacco particles and to form them into reconstituted tobacco foils which thereafter may be used in the same or similar manner as the true tobacco leaves of tobacco plants. According to these known processes, the tobacco particles which in essence thus are the waste formed during the manufacture of tobacco products, are first ground into a fine powder or dust, whereafter this powder or dust is suspended in inorganic or organic liquids, usually water under admixture of binders, as for example, cellulose derivatives. The suspension thus formed is then spread in a thin layer on a support and is dried. According to these prior art processes, as referred to hereina'bove, the amount by weight of the suspension agent, i.e., the inorganic or organic liquid, is usually a multiple of the weight of tobacco powder or dust suspended in the liquid, This, of course, means that the drying of the suspension to remove the liquid requires considerable expenditure in heat values. The heat necessary to remove the liquid is not only an important cost item, but, moreover, the heat treatment causes, in many instances, also an undesired change of the original or inherent characteristics and properties of the tobacco moiety. It is well known in the art that the drying of a tobacco dust suspension which contains a large amount of liquid negatively affects the aromatic and other qualities of the tobacco.

The foils which are artificially formed or reconstituted in this manner have to be capable of withstanding considerable mechanical stresses during the subsequent processing of the foils. In particular, these foils should not easily crumble or break. For this reason, the suspen- 'sion of the tobacco dust in the prior art processes has to be admixed not only with binders, but also with certain additives such as natural or synthetic fibers or carrier foils. These extraneous additives likewise have a tendency negatively to affect the inherent characteristics of the starting product. It is thus known that the smoke producing and aromatic characteristics of tobacco foils, artificially formed by prior art processes, are inferior to those of natural tobacco leaves.

Accordingly, it is a primary object of this invention to. provide for a procedure for forming reconstituted tobacco foil from tobacco particles which results in tobacco toils of a superior and excellent quality which is comparable to that of natural tobacco leaves.

Another object of this invention is to provide a process of the indicated nature which is easy to carry out without elaborate equipment, does not require any grinding operation, is inexpensive and which is an improvement over the prior art processes of this nature.

A further object of this invention is to provide for a process of forming plant leaves or foils from comminuted plant particles which results in plant leaves of great mechanical strength and flexibility.

Generally it is an object of this invention to improve on the art of forming reconstituted foils [from comminuted plant particles.

Briefly, and in accordance with this invention, plants and in particular tobacco foils are formed from comminuted plant particles, including particles of more than 1000 diameter by first moistening the plant particles, without prior grinding, with an amount by weight of Water or glycol which is less than the amount by weight of the plant particles and then pressure rolling the moistened mixture thus formed into foils by a plurality of rollers rotating at different speeds.

In a preferred embodiment of the invention, the foillike structures thus formed are thereafter further processed to adjust a suitable moisture content therein accordance with the use to which the foils are to be put. The adjustment of the moisture content in tobacco foils is generally being referred to as conditioning. The inventive process yields surprising results and unexpectedly overcomes the serious drawbacks of the prior art processes.

From a practical point of view, the inventive process is advantageously carried out with tobacco particles of various sizes including particles of more than 1000 diameter. It should be appreciated that mixtures of particles emanating from different portions of tobacco plants may successfully be processed into the inventive foils. For example, it is feasible to use mixtures including particles emanating from the stalks, stems, the stipules and ribs of the original tobacco leaves.

The starting material, to wit, the comminuted plant particles, is first moistened with water and/ or glycol. No prior grinding is to be efiected. The amount of the liquid is calculated in dependence on the weight of the particles. As previously mentioned, the weight of the liquid must be less than the weight of the particles. With a view to effecting proper moistening of the material, this process step is advantageously carried out in a mechanical kneading device.

In this manner, a crumb-like moist mass is obtained which subsequently is shaped into foil-like structures, usually referred to in the tobacco art as flakes. This shaping is carried out under pressure of preferably more than atmospheres by passing the mass through the nip or bite between rollers. The shaping may be effected in several stages under the same or different pressures. It is thus, for example, feasible first to subject the moist mass to a compression treatment with relatively low pressure and thereafter, in the subsequent stages, to increase the pressure. In order to be able to operate continuously,

the compressing or compacting procedure may be carried out in a roller frame having a plurality of rollers rotating at different speeds.

The plant material may also be admixed with additives such as aromatic agents, coloring agents and the like. These additives may, for example, be in the form of comminuted fruit, sugar products and the like. The admixture of such additives can within the scope of this invention be effected prior, during or after the pressure shaping.

For the formation of tobacco foils from comminuted tobacco particles, it is within the scope of this invention to add to the tobacco particles those additives which are commonly admixed with natural tobacco products. Thus, all those materials and substances which according to the tobacco laws of the various countries are permissible additives to tobacco may be incorporated into the foil structures. In this manner, tobacco foils are obtained which can be subsequently processed in the same manner as natural tobacco leaves. The tobacco foils or flakes produced in accordance with this invention may thus in the same manner as natural tobacco leaves be subjected to thermic and/ or mechanical treatments and saucing, and the inventive tobacco leaves are eminently suitable for the production of all kinds of tobacco products.

The invention will now be described by examples, it being understood that these examples are given by way of illustration and not by way of limitation and that many changes in process conditions in general can be effected without affecting in any way the scope and spirit of this invention as recited in the appended claims.

EXAMPLE I One kilogram of coarsely comminuted cigar tobacco, containing an appreciable amount of particles of more than 1000 diameter, was moistened with a solution consisting of 100 grams of plum syrup and 600 ml. of water. The moistening was effected so as to obtain a homogeneously moistened mass. This moist crumb-like tobacco mass was then kneaded under pressure and subsequently fed to a multiple roller frame. The pressure of the individual rollers of the frame was adjustable and the pressure increased from roller to roller. The rollers rotated at different speeds. At the end of the roller frame, a continuous foil was formed which was cut into suitable sizes. These foils were thereafter processed into tobacco products in known manner.

EXAMPLE II One kilogram of tobacco waste, essentially consisting of small fragments of tobacco leaves and 500 grams of comminuted tobacco stems and stalks were mixed with 100 grams of comminuted leaves of Liatris odoratissz'ma, 50 grams of cocoa bean powder and grams of titanium dioxide. The mixture thus obtained was moistened with a solution consisting of Cumarin grams 5 Licorice do 80 Invert sugar do 100 Citric acid do 30 1,3-butyleneglycol do Water ml 700 Mixing was effected in a mechanical kneader. A crumblike moist mass was formed in this manner which was further processed in the device shown in the drawings.

The inventive process is advantageously carried out in apparatus of the kind illustrated in the accompanying drawing wherein:

FIG. 1 is a diagrammatic view of the total arrangement; and

FIG. 2 is a plan view of a detail of the apparatus illustrating a conveyor belt with deflecting means.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the drawings, reference numerals 1,

2 and 3 indicate storage containers for tobacco particles of various sizes, including particles of more than 1000p. diameter. Container 1 may, for example, contain tobacco dust, while container 2 contains larger tobacco waste particles. Container 3 may accommodate comminuted tobacco ribs or the like.

Water insoluble tobacco additives in powder form are contained in the storage containers 8 and 9. Container 8 may thus, for example, hold color pigments, while container 9 stores titanium dioxide.

Containers 10, 11, 12 and 13 are provided for the liquid ingredients. For example, container 10 may be filled with an organic liquid such as glycol, while container 11 is supplied with solutions of moisture-retaining agents which are dissolved in water or organic liquids. Container 12, in turn, may hold binders which are dissolved in water or organic liquids, while container 13 accommodates solutions of agents which improve the burning characteristics of the final tobacco products. It will be appreciated that the several containers could be replaced by a collecting vessel in which the various additives are dissolved in suitable amounts.

Reference numerals 14a, 14b and 14c refer to control devices which are set so that they automatically permit the passage of predetermined amounts of material .from the storage containers to the feed lines terminating in the kneading devices 15:: or 15b respectively. The control devices are thus set in advance to permit the passage of predetermined amounts of the various materials. The flow of the various materials to the feed lines of the kneading devices 15a or 15b takes place through conduits or pipes as diagrammatically indicated. A line 16 is also provided for the supply of water. The flow of the water through line 16 is controlled by the valve 160.

In respect to the substance supplied in liquid form, it has been found to be advantageous to convey them first through lines 18 and 17 to a mixer 19 where the various liquids are stirred by the agitating means 20 to form a homogeneous solution. The homogeneous solution then flows from the mixing container 19 through lines 21 and 22, respectively, into the kneaders 15a and 15b. The dry components, by contrast, are conveyed through the lines 23 and 24 to the hopper 25. The hopper discharges onto a defiectable conveyor belt 26 which, corresponding to its setting, discharges either into the kneading vessel 15a or the kneading vessel 15b.

Vane-like kneading means 27 are rotatably arranged within the kneading vessels 15a and 15b. The liquid and solid material supplied to the kneaders 15a and 15b is thus thoroughly mixed to form a moist, crumb-like mass. This mass is then conveyed by the conveyor belt 28 to a filling funnel 29 arranged above a first roller mechanism 30. The roller mechanism 30 has in its upper portion, below the discharge of the funnel 29 a pair of take-in rollers 31 with knurled or roughened surface. The material falling through the funnel 29 thus passes through the nip of the roller pair 31. Three rollers 32 with roughened surface are arranged below the take-in rollers 31, the path of the material discharged from the roller pair 31 through the nips between the rollers 32 being indicated in the drawing. A stripping means is provided at the lower roller nip. The material, in accordance with the embodiment here shown, then passes through a receiving funnel 34 and from there is discharged to a second roller mechanism 33, having three rollers 35. The material, after having passed through the nips of the rollers 35, falls onto a conveyor belt 36 which conveys the material to a receiver 34a from where it is discharged to the next roller mechanism 37. The roller mechanism 37 also comprises three rollers 38. The material thus enters the lower nip of the rollers 38, passes around the central roller and between the nip between the central and upper rollers. At this point the material is in the form of individual fleece pieces of relatively loose cohesion. The stripped-off individual pieces fall onto a conveyor belt 39 which feeds the pieces,

through a receiver 34b, to a final roller mechanism 40 also comprising three rollers 41.

As seen from FIG. 2, the conveyor belt 39 has stationary marginal ledges 39a which are provided with bafile or impact members 39b. These members 3% are arranged separately or in opposing pairs at the ledges 39a and can be brought into different angular positions in which they are arrested. When the material strikes the bafie surfaces, its passage is of course obstructed and in this manner the direction of feed of the material can be changed or deflected in a desired manner. In this manner a certain reorientation of the individual pieces is accomplished.

During its passage through the nips of the roller mechanism 40, the material discharged from the conveyor belt 39 is compacted in such a manner that it leaves the roller mechanism 40 in the form of a relatively loose tobacco fleece or web which can be lifted by means of a suitable stripping means onto the conveyor belt 42. The fleece may be conveyed by the conveyor belt 42 directly to a final treatment station consisting of a multiple roller mechanism 43. However, if desired, and dependent on space and working conditions, the fleece may first be supplied to a storage container (not shown) and from there be fed by the conveyor belt 44 to the roller mechanism 43. The multiple roller mechanism 43 comprises a funnel device 45 from. which the web material is fed to the intake nip of the roller mechanism and from there around the individual rollers rotating in opposite directions. The material is discharged from the last roller in the form of a dense, continuous, uniform foil and is taken off by means of a stripper 46 to be conveyed onto an endless conveyor belt 47. The conveyor 47 feeds the foil to a moisture conditioning station (not shown).

In the present embodiment the mounting means for the central rollers of the roller mechanisms 33, 37, 40 and 43 are stationarily arranged at the wall of the respective frame or casing. By contrast, the mountings for the other rollers are adjustable in such a manner that the nips or bites formed between the central roller and the respective adjacent rollers can be varied in a desired manner. After the desired nip width has been set, mountings of the respective rollers are then arrested.

The distance from roller mechanism to roller mechanism is preferably about 2.5-3.5 meters.

The rotational speed of the rollers is also adjustable. It is also advantageous to provide means for controlling the temperature of the rollers since it has been found that the best results are obtained if the rollers operate at a temperature of about 20 C.

In accordance with the invention it has been found that excellent results are obtained if the width of the nips of the individual roller mechanisms are decreased in direction of the traveling material to be compacted. For example, if the nip width in the first roller mechanism is about 0.1 mm., the width in the next roller mechanism may be 0.08 mm. and in the third roller mechanism about 0.075 mm. In this manner :a gradually increasing pressure is exerted on the material, resulting in an excellent final product.

In respect to the pressure it has been found that excellent results are obtained if the pressure in the first roller mechanism is between 25 to 50 kg./cm. in the second roller mechanism between 40-75 kg./cm. and in the third roller mechanism about between 50-90 kg./cm.

The nip in the final multi-roller mechanism should be extremely narrow so that the fleece or foil discharged from this final mechanism is compact and continuous and can be taken ofi? by a stripping means without falling apart. The pressure in this final roller mechanism is about 100 kg./cm. which corresponds to a pressure of about 6000 kg. calculated on the total nip length. Due to this pressure and the rolling effect which takes place when the material passes through the nip and due to the provision of several nips of similar pressure conditions through which the material passes, the tobacco foil is continuously compacted to an ever increasing extent so that it finally forms a foil of great strength.

It is of importance for the successful performance of the inventive process that the rollers of the individual roller mechanisms rotate with diflerent speeds, the speed increasing in the direction of travel. Further, adjacent rollers should rotate in opposite directions.

If a roller mechanism is provided which, for example, has four rollers, very good results are obtained if the following speeds are adhered to:

First rollerRotational speed 5 m./second; Second roller-Rotational speed 9 m./second; Third rollerRotational speed 15 m./ second; Fourth roller-Rotational speed 25 m./second.

Due to the gradually increasing speed, the tobacco foil which is formed during the passage of the material through the nips between the rollers is without difficulty transferred from one roller surface to the next one. The fleece is gradually compacted while moving from roller to roller.

What is claimed is:

1. A process of forming reconstituted tobacco foils which essentially consists of:

(a) moistening and kneading, without grinding, tobacco particles of various sizes including particles of more than 1000 diameter as they are obtained from tobacco waste processing, with a quantity by weight of an inert liquid selected from the group consisting of water and glycol which is less than the weight of the particles;

(b) thereafter pressure-rolling the moistened particles by a plurality of rollers rotating at different speeds under a pressure of a total of more than kg./cm. into a foil-like structure; and

(c) conditioning the foil-like structure by adjusting its moisture content.

2. A process as claimed in claim 1, wherein the moistened particles are passed through the nips formed by said plurality of rollers, adjacent rollers rotating in opposite direction.

3. A process as claimed in claim 1, wherein the pressure rolling is effected by passing the moistened particles through the nips formed between rollers of a plurality of roller mechanism, each roller mechanism having a plurality of rollers, the rotational speed of the rollers increasing in the direction of travel of the particles.

4. A process as claimed in claim 3, wherein adjacent rollers of each mechanism rotate in opposite directions.

5. A process as claimed in claim 3, wherein the moistened particles are passed through at least three roller mechanisms, each mechanism having a plurality of rollers, the particles being subjected in the first roller mechanism to a pressure of about between 25 to 50 kg./cm. in the second roller mechanism to a pressure of between about 40-75 kg./cm. and in the third roller mechanism to a pressure of between about 50-90 kg./cm.

6. A process as claimed in claim 5, wherein the particles discharged from said third roller mechanism are fed to a fourth roller mechanism having a plurality of rollers in which the particles are subjected to a pressure of about 100 kg./cm.

7. A process as claimed in claim 3, wherein the pressure rolling is effected by passing the moistened particles through at least three roller mechanisms, each having a plurality of rollers, the nip width between the rollers in the first mechanism being about 0.1 mm., in the second roller mechanism being about 0.08 mm. and in the third four rollers, the first roller rotating with a speed of about 5 m./second, the second roller rotating with a speed of about 9 m./second, the third roller rotating with a speed 7 8 of about 15 m./second and the fourth roller rotating with 3,203,432 8/1965 Green et a1. 131-14O a speed of about 25 rn./sec0nd, adjacent rollers of said 3,209 763 10/1965 Parmelb et a1. 131140 mechanism rotating in opposite directions.

MELVIN D. REIN, Primary Examiner. References Cited 5 UNITED STATES PATENTS C1? 2,707,472 5/1955 Iurgenson et a1 13 15 13117 3,136,321 6/1964 Davis 131-17 X 

